Hood latch assembly

ABSTRACT

A VEHICLE HOOD LATCH ASSEMBLY HAVING A PRIMARY LATCH, A SECONDARY LATCH, AND A HOOD RELEASE MECHANISM WHEREBY THE PRIMARY LATCH IS UNLATCHED BY A SOLENOID ACTUATED BY A MASTER CONTROL FROM THE PASSENGER COMPARTMENT TO RELEASE A CATCH MEMBER ON THE HOOD LATCH TO, IN TURN, RELEASE THE PRIMARY LATCH, AND THE SECONDARY LATCH BEING UNLATCHED BY A RELEASE LEVER PULLED FROM THE FRONT OF THE VEHICLE TO ALLOW THE HOOD TO OPEN WHILE SIMULTANEOUSLY LATCHING THE CATCH MEMBER SO THAT IT IS AGAIN READY TO BE RELEASED BY THE MASTER CONTROL.

D. W. HERMAN Feb. 23, 1971 HOOD LATCH AS SEMBLY 2 Sheets-Sheet 1 Filed Aug. 26, 1969 Hie??? Ylllllll lNVlf/VTUR.

flenmls 11/ Zierman ATTORNEY f F b, 23, 1971 I 0'. WrBERMAN 3,565,476

HOOD LATCH ASSEMBLY Filed Aug. 26. 1969 2 Sheets-Sheet 2' INVENTOR. aaenms 11/ 6817/7612 ATTORNEY United States Patent 3,565,476 HOOD LATCH ASSEMBLY Dennis W. Berman, Sterling Heights, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Aug. 26, 1969, Ser. No. 853,081

Int. Cl. Eb 65/12; E05c 3/06 US. Cl. 292-201 '1 Claims ABSTRACT OF THE DISCLOSURE A vehicle hood latch assembly having a primary latch, a secondary latch, and a hood release mechanism Whereby the primary latch is unlatched by a solenoid actuated by a master control from the passenger compartment to release a catch member on the hood latch to, in turn, release the primary latch, and the secondary latch being unlatched by a release lever pulled from the front of the vehicle to allow the hood to open While simultaneously latching the catch member so that it is again ready to be released by the master control.

The present invention relates to a hood latch assembly having an improved release mechanism adapted for the sequential release of a primary latch and a secondary latch.

It is common practice with vehicle front hood members to utilize both a keeper or primary latch to retain the hood in a tightly closed position as well as a safety or secondary latch which prevents full hood opening in the event the keeper or primary latch becomes disengaged. Further, it is broadly known to utilize a common operating member for sequentially achieving the disengaging action of both a keeper latch and a safety latch. Because of the use of a common operating member in the prior art devices, it was diflicult to prevent unauthorized opening of the hood.

Accordingly, the primary object of this invention is to improve a hood latch assembly whereby a sequential release of the keeper latch and safety latch can only be accomplished by sequential operation of two separate operating members, one from the passenger compartment of the vehicle and the other from the front exterior of the vehicle. Another object of this invention is to improve a hood latch assembly whereby sequential operation of the keeper latch and safety latch is accomplished by a power actuated source from within the passenger compartment of the vehicle and a mechanical member actuated from the exterior of the vehicle.

According to the embodiment of the invention disclosed, these and other objects of the invention are achieved by providing a hood latch assembly including a primary latch and a secondary latch, spring biased to an unlatched position and a latched position, respectively. When the primary latch is moved to a latched position by engagement with a striker, it is releasably retained in this position by biased pawl detent means. A release lever is pivotally mounted to effect unlatching of the secondary latch. Sequential release of the primary and secondary latches is effected by a solenoid released spring biased primary release lever engaging the pawl detent means to release the primary latch after which manual movement of a secondary release handle pivots a secondary release member to engage and pivot the release-lever to unlatch the secondary latch while at the same time resetting the primary release lever for the next release by the solenoid and allowing the pawl detent means to return to a ready position to catch and hold the primary latch during the next closure of the hood.

For a better understanding of the invention, as well as other objects and further features thereof, reference is had to the following detailed description of the invention to be read in connection with the accompanying drawings, wherein:

FIG. 1 is a front elevational view of the hood latch assembly;

FIG. 2 is a view of the hood latch assembly taken along line 2-2 of FIG. 1 with parts removed to show details of the unlatching mechanism;

FIG. 3 is a top view of the hood latch assembly with the primary latch and secondary latch removed to show the details of the unlatching mechanism; and

FIG. 4 is a sectional view taken along line 44 of FIG. 3.

While the present invention is of general utility in any environment in which both a keeper latch and safety latch are desired, the invention will be described as employed on the front hood of an automotive vehicle, not shown. Referring particularly to FIG. 1, the hood latch mechanism, indicated generally at 10, is secured to a transverse plate 12 of a front body portion of the vehicle and is adapted to coact with a striker 14 suitably secured to the underside of the hood, not shown, of the vehicle.

In the embodiment of the invention illustrated, the transverse plate 12 of the front vehicle body portion is shown as having an upstanding latch casing 21 secured thereto as by bolts 22 extending through spaced projecting flanged portions 23 of the latch casing.

The latch casing 21 may be formed from a single piece of sheet metal, as by a stamping operation, and has a rounded nose 24 guiding the casing for movement within striker 14 on the hood. As shown in FIG. 1, the outstanding legs of the striker 14 are adapted to be engaged by a safety or secondary latch 25 pivotally mounted within the casing and biased in projected relation with respect to the case toward the latched position relative to the striker and to be engaged by the keeper or primary latch 26 which is normally biased to the unlatched position. Both the primary latch, including its take-up feature, and the secondary latch are of a well-known type presently used on hood latches of motor vehicles.

The primary latch 26 is shown in FIG. 1 as being projected from the opposite side of the casing from the secondary latch 25 and as having a locking slot 27 therein, engageable with the striker. The primary latch is pivoted intermediate its ends within the latch casing on a pivot pin 28 rivited or secondary latch 25 is pivotally mounted on the latch casing adjacent the lower end thereof by a pivot pin '30 also secured to the wall of the casing. The primary latch 26 is normally biased in a clockwise direction to an unlatched position While the secondary latch is normally biased to a latched position by means of a coiled torsion spring 31 encircling the pivot pin 28 with one leg of the torsion spring being hooked on the primary latch 26 and the other leg being hooked over the secondary latch 25.

Thus, as the hood is lowered, the striker 14 Will first engage the secondary latch 25 to cam it in a counterclockwise direction as seen in FIG. 1 to the position shown by the broken line until that portion of the striker rides past the hook engaging portion of this latch at which time the secondary latch is again spring biased toward the latched position. Further downward movement of the striker will then cause the opposite side of the striker to engage the inturned portion of the locking slot 27 of primary latch 26 forcing it to rotate in a counterclockwise direction as seen in FIG. 1 to the latched position, shown by the broken line, against the bias of the torsion spring 31. In the latched position, the primary latch is taken up on and held in a latched position by a detent in the form of a pawl 32 engageable with ratchet teeth 33 on the opposite side of the primary latch 26 from the locking slot 27. The pawl 32 and a release lever 34 for the secondary latch 25 are pivotally supported on pivot pin 35 secured to the lower end of the latch casing and at the opposite side thereof from the pivot pin 30. Coiled torsion spring 36 is mounted to encircle the pivot pin with one leg of the torsion spring 36 engaging a leg of the pawl 32 and the other leg of the spring engaging an apertured portion of the latch casing whereby the pawl is normally biased in a counterclockwise direction to engage the teeth of the primary latch. A second coiled torsion spring 37 is also mounted to encircle the pivot pin 35 with one leg of this torsion spring engaging a leg of the release lever 34 and the other leg of the spring engaging the apertured portion of the latch casing to also bias the release lever in a counterclockwise direction. Thus pawl 32 is normally biased toward engagement with primary latch 26 to retain it by engagement with the ratchet teeth thereon in a latched position while release lever 34 is normally biased out of contact with the secondary latch 25 to permit it to be normally biased to the latched position for engagement with striker 14.

When the latch assembly is in latched condition, disengagement of pawl 32 from the primary latch 26 by clockwise rotation of the pawl 32, as seen in FIG. 1, permits coiled spring 31 to rotate the primary latch 26 in a clockwise direction to disengage the latter from striker 14 thereby permitting at least a partial opening of the hood. While permitting a partial opening of the hood, disengagement of primary latch 26 from the striker 14 does not enable a complete opening of the hood since as the striker 14 moves upward during opening of the hood it will contact the extended portion of secondary latch 25 which as previously mentioned is normally biased to the latched position to thereby restrain the hood from further opening movement. To effect full opening of the hood, the secondary latch 25 must be actuated or released by clockwise rotation of release lever 34 whereby the leg 34a thereon engages a projecting portion 38 of the secondary latch 25 and in so doing to impart a counterclockwise rotation to the secondary latch 25 moving it out of latching engagement with striker 14.

Now to be described are the means to provide the following sequential steps of operation in opening and closing the engine compartment hood of a vehicle using the subject hood latch assembly:

A master control is actuated, for example, from within the passenger compartment of the vehicle which releases a catch member to in turn release the primary latch;

A safety release handle is pulled from the front of the vehicle releasing the secondary latch allowing the hood to open fully while simultaneously latching the catch member so that it is again ready to be released by the master control; and

The hood is closed latching the primary latch and secondary latch to maintain the hood in the closed position until the above sequence is repeated.

As shown best in FIG. 3, a C-shaped primary release lever 40 is pivotally mounted intermediate the legs 40a and 40b thereof by headed stud 41 to a lateral forward leg of latch casing 21, the leg 40a being positioned to engage pawl 32 to rotate it clockwise as seen in FIG. 1 when the primary release lever 40 is rotated in a counterclockwise direction as seen in FIG. 3 by means of compression spring 42. Spring 42 has one end abutting against the front wall of latch casing 21 and the other end abutting an upstanding flange portion of leg 40b of the release lever 40 with the spring 42 thus encircling a locking member 43. Locking member 43 extends through a slot 44 in the upstanding flange portion of leg 40b, through the spring 42 and then through a slot in latch casing 21, this end of the locking member 43 terminating in an inverted book 45 which is engageable by the upright notched leg of catch member 46 which is suitably positioned for vertical up and down movement and connected to a suitable actuator for actuation, preferably from the interior of the vehicle. In the preferred embodiment disclosed, the catch member is secured to the armature 50 of a solenoid 51. Solenoid 51, mounted by bracket 52 to a depending portion of latch casing 21, is connected via normally open switch 53, which may be mounted on the dash panel of the vehicle, to the vehicle battery 54. The solenoid 51, of a well-known type, is provided with an internal spring, not shown, to normally bias the armature to an extended position.

The other end of the locking lever 43 is provided with a flanged portion whereby the locking lever 43 is pivotally connected by pivot pin 55 to one end of lever 56 which is in turn pivotally mounted intermediate its ends by stud 57 to a lateral forward extension of latch casing 21. At its other end, lever 56 is coupled to secondary release handle 60 by double shouldered stud 58 which extends through a slot 61 intermediate the ends of secondary release handle 60 and through a slot 62 in latch casing 21.

Secondary release handle 60 extends forwardly, as seen in FIGS. 2 and 3, toward the front of the vehicle with its most forward portion formed with a hand grip 63 in position to be accessible from the front of the vehicle. The opposite end of the secondary release handle 60 is pivotally connected by pivot pin 64 to secondary release member or lever 65 which is pivotally mounted by shoulder stud pin 66 to the side of latch casing 21 whereby as the secondary release handle 60 is pulled forward, to the left as seen in FIG. 2, the secondary release member 65 is rotated counterclockwise, as seen in this figure, to have the cam portion 68 thereon engage release lever 34 to effect disengagement or release of the secondary latch 25, as previously described.

Normally, the secondary release member 65 is biased in a clockwise direction, as seen in FIG. 2, by coiled torsion spring 67 which encircles shoulder stud pin 66 with one leg of the spring hooked over the edge of latch casing 21 and the other leg engaging a turned out tab 69 of the secondary release member. Movement of the secondary release member 65 in this direction is limited by stop 65a thereon engaging a flanged portion 23 of latch casing 21.

From the above description, it is aparent that the primary release lever 40 is, in effect, actuated by an energy storage device, that is, spring 42 which is armed by the operator as he pulls on secondary release handle 60 to release the secondary latch. Pulling forward on the secondary release handle will, through the linkage described, force a compression of spring 42, the spring then being held in compression by engagement of catch member 46 with the hook 45 of locking member 43 until again released by actuation of the solenoid 51. The energy thus stored in spring 42 is available for use to unlatch the primary latch whenever desired from the interior of the vehicle.

The sequential operation of the latch mechanism and, particularly, the relationship of the elements thereof during this operation will now be described. Assuming that the hood is in the closed position, when the operator wishes to open the hood he must first close switch 53 in the passenger compartment to energize solenoid 51. As the solenoid 51 is energized, armature 50 is retracted pulling with it the catch member 46 to release lock member 43 thus permitting compression spring 42 to pivot release lever 40 about the axis of headed stud 41 from the position shown by the broken lines in a counterclockwise direction, as seen in FIG. 3. As the release lever 40 is thus pivoted the leg 40a thereof will engage pawl 32 to rotate it out of engagement with the ratchet teeth 33 of primary latch 26. The primary latch 26 is now free to be biased by spring 31 to the unlatched position to release striker 14, allowing the hood to move to a partially open position at which position it is then retained by engagement of the striker 14 with secondary latch 25. As the release lever is pivoted in this counterclockwise direction, it engages the upstanding portion of locking member 43 to move it to the left, as seen in FIG. 4, to pivot lever 56 in a counterclockwise direction, as seen in FIG. 3. When this occurs, the opposite end of lever 56 moves from the left hand end of slot 61 in secondary release handle 60, to the right hand end of the slot as seen in FIG. 3.

To fully release the hood, the secondary release handle 60 is pulled from the front of the hood, moving it to the left, as seen in FIG. 3, pivoting secondary release member 65 in a counterclockwise direction, as seen in FIG. 2, into engagement with release lever 34 to rotate it in a clockwise direction, as seen in FIG. 1. Release lever 34 is thus pivoted into engagement with the projecting portion 38 of secondary latch 25 to move this latch to the unlatched position out of engagement with striker 14 completely releasing the hood whereby it can then be moved to the fully open position. At the same time that the forward pull of secondary release handle 60 is actuating secondary release member 65, it is also engaging stud 58 to move it to the left, as seen in FIG. 3, pivoting lever 56 about the axis of stud 57 in a clockwise direction, as seen in this same figure. This pivotal movement of lever 56 will force locking member 43 to the right, as seen in this same figure, against the biasing action of spring 42 into the catch member 46. The tapered end portion of locking member 43 adjacent to hook 45 thereon will cam the catch member 46 downward and the spring, not shown, of the solenoid 51 acting on the armature 50 will return the catch member 46 to the raised position where the locking member 43 hooks onto the catch member 46 to in effect reset the solenoid 51. Movement of the locking member 43 to the right, as just described, will also cause pivotal movement of the release lever 40 in a clockwise direction to the position shown by the broken lines in FIG. 3, in which it is out of engagement with pawl 32, thus releasing the pawl 32 to be pivoted by spring 36 into a ready position to engage the ratchet teeth 33 of primary latch 26 to hold the primary latch when again moved to the latched position. The hood is now in the open position and the hood latch assembly is reset.

When the hood is again closed, the striker 14, as the hood is lowered, will first engage the upper cam portion of secondary latch 25 to cam it temporarily to the unlatched position as it passes past the secondary latch 25, after which the spring 31 biases this latch back to the latched position. The striker 14, as it is further lowered, engages the primary latch 26 rotating it to the latched position, shown by broken lines in FIG. 1, where the striker 14 is held by the primary latch 26 whose release is then prevented by engagement of pawl 32 with the ratchet teeth 33 thereon until the hood opening operation is repeated.

While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.

What is claimed is:

1. A hood latch assembly for a motor vehicle including a latch casing, primary latch means swingably mounted on said latch casing for movement between unlatched and latched positions, detent means positioned for releasably holding said primary latch means in said latched position, secondary latch means swingably mounted on said latch casing for movement between latched and unlatched positions, lever means engageable with said secondary latch means for moving said secondary latch means to said unlatched position, primary latch release means including an energy storage device operative from the interior of the vehicle for affecting movement of said detent means to release said primary latch means, secondary latch release means including a manually actuated release handle accessible from the exterior of the vehicle to temporarily move said secondary latch means to said unlatched position, and coupling means intercom necting said primary latch release means and said secondary latch release means for sequentially controlling the unlatching of said primary latch means and said secondary latch means, said means effecting arming of said energy storage device during actuation of said secondary latch release means.

2. A hood latch assembly according to claim 1 wherein said primary latch release means includes primary release means positioned for pivotal movement from a position out of engagement with said detent means to a position engaging and releasing said detent and said energy storage device includes power means positioned to move said primary release means to said position engaging and releasing said detent, a locking member connected to said coupling means and engaging said primary release means to move said primary release means to said position out of engagement with said detent means, catch means positioned to lock said locking member upon actuation of said secondary release means, and release means operative on said catch means to release said locking member.

3. A hood latch assembly according to claim 2 wherein said secondary latch release means includes a lever pivotally mounted on said latch casing for engagement with said lever means to move said secondary latch means to said unlatched position and release handle means connected to said lever for effecting the release of said secondary latch means.

4. A hood latch assembly including a latch casing, primary latch means swingably mounted on said latch casing for movement between unlatched and latched positions, detent means positioned for releasably holding said primary latch means in said latched position, a secondary latch means swingably mounted on said latch casing for movement between latched and unlatched positions, lever means engageable with said secondary latch for moving said secondary latch means to said unlatched position, primary release means positioned for movement from a non-engaging position relative to said detent means to a detent means engaging position for releasing said primary, latch means, primary actuator means for selectively moving said primary release means to said detent engaging position, secondary latch release means positioned to engage said lever means to effect movement of said secondary latch means to said unlatched position, and coupling means interconnected between said secondary release means and said primary actuator means for moving said primary release means to said non-engaging position when said secondary release means is actuated to alfect movement of said secondary altch means to said unlatched position.

5. A hood latch assembly according to claim 4 wherein said primary actuator means includes power means positioned to move said primary release means to said detent means engaging position, a locking member connected to said coupling means and engaging said primary release means to move said primary release means to said non-engaging position, catch means positioned to engage said locking member to restrain movement of said locking member, and catch release means positioned to move said catch means to release said locking member, said catch means being operative to engage said locking member upon actuation of the secondary release means.

6. A hood latch assembly according to claim 5 wherein said secondary latch release means includes a lever pivotally mounted for movement from a first position out of engagement with said lever means to a second position to engage said lever means for moving said secondary latch means to said unlatched position, means to normally bias said lever to said first position, and a manually movable release handle secured to said lever and projecting therefrom for moving said lever to said second position.

7. A hood latch assembly according to claim 6 wherein said coupling means includes a coupling lever pivotally secured at one end to said locking member and at its other end pivotally and slidably secured to said release 7 8 handle and to said latch casing, said coupling lever be- 3,236,551 2/1966 Nash 292-11 ing pivotally secured intermediate its ends to said latch 3,378,289 4/1968 Beckman 292-31 casmg' References Cited MARVIN A. CHAMPION, Primary Examiner 5 L. Assistant Examiner 2,809,064 10/1957 Dlugatch 292-226 3,200,623 8/1965 Peters 70279 70 241;292 .11,210,33 3

" UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3.565,476 Dated February 23, 1971 Inventr(5) Dennis W. Berman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 64, after "release", delete the hyphen Column 2, line 45, after "or", insert otherwise secured to the wall of the latch casing while the Column 6, line 48, "altch" should read latch Signed and sealed this 17th day of August 1971 (SEAL) Attest:

EDWARD M.FLETGHER,JR. WILLIAM E. SGHUYLER, JR. Attesting, Officer Commissioner of Patents 

